Currently, most amphibian populations in the world exist under the influence of numerous stress factors. Among them, the main factors that affect almost all terrestrial animals, namely, the fragmentation of habitats, environmental pollution and anthropic transformation of landscapes. Moreover, those factors are joined by negative causes that affect only amphibians – specific viral and fungal infections: ranaviruses (Ambystoma tigrinum virus (ATV), Bohle iridovirus (BIV), and frog virus 3) (also dangerous for some reptiles) and chytrid fungi (Batrachochytrium dendrobatidis and B. salamandrivorans). All these factors are one of the main reasons for the current global decline of amphibian populations in the world. In today's world, agricultural chemicals are one of the most important in terms of toxicity, environmental emissions and total area of impact. Among them, a significant proportion are formed by synthetic insecticides, which include pyrethroids and neonicotinoids. Pollution by these substances has a negative impact on amphibian populations, despite the relatively short period of their life in the environment. The vast majority of studies on the effects of pyrethroid and neonicotinoid insecticides were made in laboratory experiments with the larval stages of tailless amphibians. Tadpoles are easy to get in sufficient quantities and kept in the laboratory. Cypermethrin reduces the viability of tadpoles and causes precocious metamorphosis of survived larvae. However, in a combination with other pesticides, it delays metamorphosis. In addition, embryos were more resistant to pyrethroids than tadpoles. Pyrethroid pesticides cause spasms indicating adverse neurological effects. Formation of oral apparatus abnormalities in tadpoles, anisochromasia and increasing number of immature erythrocytes are also caused by pyrethroids. Neonicotinoids show similar effects. Under the action of imidacloprid the erythrocytes are also disturbed that is showed up in the DNA damage and micronuclei formation. Neurological disorders are manifested in the ability to perceive or respond to a predator, disorientation, erratic movement and loss of balance. Pyrethroids and neonicotinoids have been shown cause a variety of disorders: increase mortality and reduce survival of tadpoles; have a teratogenic effect and affect the metamorphosis and morphological parameters of amphibians; change many biochemical parameters that characterize the protein metabolism and oxidative stress; have genotoxic effects and affect the state of the nervous system and animal behaviour. Most of these parameters are proposed for use as biomarkers of pesticide intoxication.

Differences in the herpetofauna of the shelterbelts, which are located at different distances from the fields treated with pesticides, have been studied. It was found that the herpetofauna of artificial forest plantations on the right bank of the Samara River consists of five species: Bufotes viridis, Pelobates vespertinus, Natrix natrix, Coronella austriaca and Lacerta agilis. The grass snake was only found in forest plantations that remote at a distance of 5 kilometres from agrocenoses and could not be treated with pesticides. In the studied areas, two species of snakes (C. austriaca and N. natrix) had the lowest numbers. Amphibians and the sand lizard are the most numerous animals in both groups of shelterbelts. The highest indicator of relative dominance in the herpetofauna of forest belts was observed for the sand lizard, which reflects the greater ecological plasticity of this species. The Renkonen index (more than 90%) showed the similarity of herpetofauna groups of shelterbelts both remote and adjacent to agrocenoses treated by pesticides. The herpetofauna groups of forest belts of both groups had similar indices of dominancy (0.35–0.46), alignment (0.78–0.97) and diversity according to the Shannon (1.07–1.22) and Simpson indices (0.29– 0.35). The lowest indicator of species richness (0.48) is determined for the forest belts adjacent to agrocenoses. Thus, artificial forest plantations that are directly affected by agricultural activities (pesticide use, reduction in food, etc.) can also act as refugia to maintain biodiversity. Nevertheless, this will depend on the amount and duration of pesticide use, so further research is needed for definitive conclusions. Forest belts, which have existed for half a century or more, are a kind of separate ecosystems that can help in understanding various issues of Zoology (fauna and species distribution), Ecology (population dynamics, population structure) and microevolution (processes in new relatively isolated systems).